Introducing your company
As you begin the phone screening, remember that it is yet another opportunity for you to sell the experience of working at your company. Spend a few minutes reviewing your company and products for the candidate, as well as covering what the role entails and the sorts of problems the candidate can expect to work on if hired. You might also mention the structure of the engineering team, and the office environment in general. You have a few minutes, so feel free to go into greater detail than in the job description.
Treat the introduction like a conversation, not a lecture. A good candidate will participate and ask questions, understanding that the next part of the interview will likely involve introducing him or herself to you. Your goal should be to introduce the role in enough detail so that the candidate understands why you are asking them the questions that follow.
The introduction also helps you get the ball rolling so that you can guide the conversation. Overall...